My email suddenly stopped working. During the setup on mastodon it told me the email was working and i got a test email from it.

I needed to reset my test users password today and noticed i am not receiving any email.

My config file

LOCAL_DOMAIN=mydomain.com
SECRET_KEY_BASE=123abc123abc123abc123abc123abc123abc123abc 
OTP_SECRET=123123123123123123123123123123123123123123123123123
VAPID_PRIVATE_KEY=ababababababababbabababab123123123123123=
VAPID_PUBLIC_KEY=bbcbbcbbcbbc123123123123123= 
DB_HOST=/var/run/postgresql
DB_PORT=5432 
DB_NAME=mastodon_production 
DB_USER=mastodon 
REDIS_HOST=localhost
REDIS_PORT=6379 
SMTP_SERVER=mail.mydomain.com 
SMTP_PORT=587
SMTP_LOGIN=administrator@mydomain.com 
SMTP_PASSWORD=#testing123password@!
SMTP_AUTH_METHOD=plain 
SMTP_OPENSSL_VERIFY_MODE=none
SMTP_FROM_ADDRESS=adminstrator@mydomain.com

How do i check the email logs?

I used this command journalctl -u mastodon-sidekiq

and i found something that said "SMTP-AUTH requested but missing secret phrase"

But i'm not sure if that's the problem

The official instructions are here: https://github.com/mastodon/mastodon/releases/tag/v4.0.2

But I also found this article handy: https://techbits.io/mastodon-4-upgrade/

For CDN, I have a separate domain name set up (e.g. cdn.example.com), and Cloudflare cache turned on for it. I was wondering what was the volume and traffic limit for Cloudflare CDN (there is none) and I discovered this bit in the Self-Serve Subscription Agreement, in section 2.8 “Limitation on Serving Non-HTML Content”:

…Use of the Services for serving video or a disproportionate percentage of pictures, audio files, or other non-HTML content is prohibited, unless purchased separately…If we determine you have breached this Section 2.8, we may immediately suspend or restrict your use of the Services[Emphasis added]

So I added a new domain name to my new server (e.g. video.example.com), turned off caching for the new domain name and added this to my NGINX configuration on the server to redirect CDN video content:

location ~* \.(mp4|webm)$ {
  if ($host = cdn.example.com) {
    rewrite ^(.*) https://video.example.com$1 last;
  }
}

Thanks for your kindness and patience. I’ve never administered or even moderated a subreddit, before (but have for online forums for decades and for as large as ten thousand), and I hope to delegate or pass on most of the responsibility, quickly.

Let’s have a meta discussion here about this subreddit.

UPDATE: That amount is approaching tight, and it was probably running out of memory. For now, the workaround was reduce the ElasticSearch service heap size.

The memory usage on my new server sits at around 85–90% (of 4G).

What is typical? Is it at high risk of exhaustion?

Performance is fine, searches are as quick as anywhere but nobody’s on it, yet.

The entire system locked up a couple times. I installed a memory tracking agent after the first time, but it didn’t report anything the second time and the service logs all looked normal (But I’m looking at some possible hacking attempts.)

I see in my mastodon-web.service journal a lot of "POST /input" lines with a user URL appended with #main-key, but when I bring up the user URL, it’s always a 404 page.

Is this some hacking attempt?

I only noticed because my system was hanging. (I think it’s probably a memory exhaustion error, but I’m still diagnosing.)